Study On The Laminar Combustion Characteristics Of CH₄/RP-3 Kerosene Mixed Fuel

In order to reduce dependence on fossil fuels and realize aviation emission reduction,it has become an urgent matter for the aviation industry to develop sustainable aviation alternative fuels.LNG has been expected to be an effective alternative fuel for energy saving and emission reduction in the aviation industry.However,after vaporizing into CH₄,the volumetric calorific value of LNG decreases and it also has the disadvantages of high ignition point and slow flame propagation speed,which is not helpful to its application in aeroengines.Therefore,it seems not practical to use LNG single fuel as aviation alternative fuel.In this paper,LNG/aviation kerosene blended fuels are supposed to use as aviation alternative fuels.The laminar combustion characteristics of CH₄/RP-3 kerosene blended fuel were examined in a constant volume combustion chamber at initial temperature of 420,450,480 K and initial pressure of 0.1,0.2,0.3 MPa,the equivalent ratio range is over the range of0.7¹.5,and the methane addition ratio is from 0 to 0.8.Relevant parameters such as flame development characteristics,laminar burning velocity and combustion stability of blended fuel were obtained.And the influence of the main factors（such as initial temperature,initial pressure,equivalence ratio and methane addition ratio）on laminar combustion characteristics of CH₄/RP-3 kerosene blended fuel were analyzed.The results show that at the stoichiometric ratio,the flame structure of the blended fuel is quasi-spherical and the surface is smooth;at a high equivalence ratio or a high initial pressure,the flame front has an cell structure;the effect of initial temperature and methane addition ratio on the flame development characteristics is not obvious.With the increase of equivalence ratio,the laminar burning velocity increases first and then decreases,and reaches its maximum value at the equivalence ratio of 1.1,and the Markstein length decreases gradually;with the increase of initial temperature,the laminar burning velocity increases gradually,and the Markstein length decreases gradually;with the increase of initial pressure,both laminar burning velocity and Markstein length decrease gradually;with the increase of methane addition ratio,the laminar burning velocity decreases gradually,the Markstein length decreases at low equivalent ratio and increases at high equivalent ratio.In this paper,the study on the laminar combustion characteristics of LNG/aviation kerosene blended fuel provides a theoretical basis for its application in aeroengine.